RE: For All you 223 Fans
In the scenario above the deers 100 yrds out quartering towards you.
That would mean either he has no idea youre there and will continue to quarter towards you, at some point it will turn into a broadside shot at a closer range
or
the deer already knows youre there and isnt sure what you are, if he turns to run he will give you the broadside or quartering away shot youre after.That far away they generally dont do this fast as theyre still not sure if youre a danger.
In either case with any gun youre better off waiting a minute to see what happens IMPO